Bluebird AR, Unlock clues and explore a story around the controversial science of geoengineering.

When the world's political leaders gather in Copenhagen for next week's United Nations Climate Change conference, striking a deal to curb greenhouse pollution will be top of their agenda.

Climate scientists agree that slashing carbon dioxide emissions should be our first priority. But what if the world's collective actions aren't enough to avoid the dangerous consequences of climate change?

After all, despite years of talks and treaties, CO2 emissions are still rising. Meanwhile, recent research suggests that the climate might already be closer to potentially irreversible tipping points than anyone predicted.

These factors have led some researchers to consider a more radical, and potentially risky, approach to cooling the Earth: manipulating the global environment on a grand scale using so-called 'geoengineering' technologies.

It's not a new idea, but such concepts have generally been consigned to the fringes of climate change discussions. However there are signs this is changing.

Last September, Britain's eminent Royal Society argued that more research into geoengineering was needed to help the world prepare for the worst.

"Unless we can succeed in greatly reducing CO2 emissions we are headed for a very uncomfortable and challenging climate future, and geoengineering will be the only option left to limit further temperature increases," said Professor John Shepherd, who chaired the Royal Society's year-long investigation of the topic.

Engineering the atmosphere

Broadly speaking, there are two types of geoengineering techniques — those that aim to take the excess carbon directly out of the air, and others designed to cool the planet by reflecting some of the sun's energy.

That second category gained a boost in 2006 when the Nobel Prize-winning ozone researcher Professor Paul Crutzen suggested that we might be able to combat global warming by injecting massive amounts of sulfur into the stratosphere.

The idea is to mimic an effect that takes place when large volcanoes erupt, explains Professor Will Steffen, director of the Australian National University's climate group.

"Volcanoes eject a lot of sulfates," Steffen says. "If they're strong enough, they put it in the stratosphere and it stays up there for a couple of years or so. During that time you can actually see a dip in the global temperature because those aerosols are scattering solar radiation and less of it gets to the Earth's surface."

Those sulfate aerosols would act quickly to cool the atmosphere, but they don't hang around for long.

"They are removed from the atmosphere by natural processes and natural chemical reactions within a year or two," says Dr Will Howard, a climate researcher from the Antarctic Climate and Ecosystems Cooperative Research Centre.

"That means you would have to keep on injecting these aerosols into the atmosphere as long as you needed that shading effect. On the other hand, it means if you wanted to stop it, you could."

For now much of the research into this technique is being done using computer models, says Professor Matthew England, co-director of the University of New South Wales's Climate Change Research Centre.

"What I like is that we can go to [computer] models and take it 'off line'."

The trouble is that we simply don't understand how the atmosphere works well enough to predict what the other impacts of sulfate aerosols might be.

These might include disruptions to rainfall patterns and acid rain, Steffen says. Another downside is that shading the Earth will do nothing to reduce other negative impacts of rising CO2 levels, such as ocean acidification.

He believes the risk is too great.

"Others might argue that as a very last ditch effort we need to [inject sulfates into the stratosphere]. Well maybe that's the case, but if it gets to the point that we've got to do that then we've pretty much lost it anyway."

Fertilising the ocean

Iron can stimulate the growth of carbon-capturing plankton in the ocean, like this phytoplankton bloom in Shark Bay, Western Australia
(Source: Jeff Schmaltz/MODIS/NASA)

If human societies can't stop emitting greenhouse gasses, then perhaps we can raise the world's capacity for taking those gases back out of the atmosphere, some geoengineering advocates suggest.

Among the best-studied options in this category is using iron to stimulate the growth of carbon-capturing plankton in the ocean.

Over the past 15 years or so, several international research teams have completed trials showing that under the right conditions this approach is scientifically feasible.

"The idea is that in some parts of the ocean, the algae that would pick up carbon and store carbon in the deep ocean are limited by iron supply," explains Howard.

Experiments have shown when you add extra iron into these areas, you stimulate algal productivity.

But the same experiments have also shown that the carbon fixed by this process doesn't sink very deep into the ocean.

Howard says the key question is whether you can change that: "Can you get that carbon out of the surface ocean and into the thousands-of-metres-deep parts of the ocean where it will stay out of contact with the atmosphere for a long time?"

There are other potential problems with this approach, he warns.

"A possible consequence of fertilization of the ocean is the fact that once this carbon does sink into sub-surface waters… you'll increase that tendency toward low oxygen."

"We know there are basins in the water that have dead zones today — where the water is anoxic and nothing that requires oxygen can live. The research would need to very carefully consider those sorts of risks before you went ahead with that kind of manipulation."

Betting on biochar

On its own biochar is unlikely to remove more than a small percentage of the excess carbon in the atmosphere
(Source: BEST Energies)

Another approach that seeks to capture carbon and keep it out of the atmosphere for thousands of years is biochar.

The idea behind it is to use plants to capture carbon through the natural process of photosynthesis, and then burn the plants in the absence of oxygen, producing charcoal that can be mixed through the soil. By doing so, it is possible to capture carbon, produce energy and fertilize the soil.

The good thing about this approach, and other technologies that aim to use plants to take carbon from the atmosphere, is that you can avoid tampering with the natural ecosystem, says England. This means there is less chance of unforeseen complications.

"I have much more comfort supporting technologies that don't draw in natural ecosystems," he says. "I always use the example of cane toads to remind people what can happen when humans try to fix something in the environment by adding something new in."

But on its own biochar is unlikely to remove more than a small percentage of the excess carbon in the atmosphere, England says.

Comments (42)

Comments for this story are now closed. If you would like to have your say on this story, please email ABC Science

John Saint-Smith :

03 Dec 2009 6:49:29pm

The pause in global warming 1940-1970 has been attributed to global dimming, caused by particulates and sulfur aerosols. Recent views of China and India confirm a return, in those rapidly developing countries, to the worst visible pollution in half a century. Isn't it possible that the current 'Bolt' pause has been affected by this dimming pollution?

Old Man Winter :

07 Dec 2009 10:45:23am

Google "ClimateGate". Or better yet, Startpage.com "ClimateGate". The hockey stick graph won't hold up anymore. The planet has cooled for several years. You are all quoting junk science that has completely usurped the peer review process because it's being used solely for an agenda. That agenda unfolds at Copenhagen tomorrow.

Andrew M :

Bulldust :

08 Dec 2009 5:02:42pm

The problem is that the emails point to the perversion of the peer review process by those in pivottal IPCC roles.

I guess you skipped those emails...

Peer review in small fields like dendroclimatology (trying to use tree rings as thermometers) is fraught with issues... the field is so small there can be no genuine peer review without brining in scientists from outside the field.

Notice their alarm when a statistician pulled them up for incorrect usage of statistics (M/M as they call them).

Trees are not good thermometers and their temperature histories should not be twisted into centrepiece graphs in IPCC documents. That is what happened and it is appalling misuse of science.

Eclipse Now :

10 Dec 2009 8:29:54am

Oh Bulldust, stop reading paranoid conspiracy theories! You'd have to believe in the LARGEST and most successful conspiracy theory in mankind's history to believe climate change was a hoax perpetrated on the scientific world. Human beings are just too competitive. Any young climate scientist would love to make history (and their scientific reputation) by disproving this threat. Human beings just aren't smart enough to pull off a conspiracy theory this large, something would leak.

Are those emails that leak? Anyone who thinks so can't read. Even right wing magazines like "The Economist" call asserting so to be "Foolish!"

This GREAT Youtube explains the tree-ring issue.http://www.youtube.com/watch?v=P70SlEqX7oY

FreeinTX :

17 Dec 2009 7:19:11am

Eclipse,

There were "peer reviewed" papers saying cigarette smoking was not only safe but beneficial. That silicon breast implants were safe. That VIOXX was safe. Even after that particular group of drugs killed over 100,000 people, Vioxx remained on the shelf because of "scientific review." If there were to have been a "peer review" far enough back in history, there would have been papers that showed the Earth was flat, and leeches worked.But the biggest example of a corrupted "peer review" process, other than the one being exposed with Climategate, is the Piltdown man.

For over 40 years scientists wrote "peer reviewed" papers that insisted that a human skull, with a pig bone lower jaw attached to it, was absolute proof of evolution. 40 YEARS of "settled science" until someone outside of their little "peer review" party managed to get close enough to expose the fraud. That fraud being the fact that scientists, desperate to prove evolution and get millions in grants, decided it was ok to take a bone from a pig, attach it to a human skull, and say "EUREKA!!!"

10 straight years of cooling, a trend whose lack of explination caused the scientists at the CRU, itself, to say that it was a travesty that they could not explain it.

Polar Bear pop's at record highs. San Fransisco and Galveston reporting lowering sea levels. Alaskan Glaciers largest in 250 years. Artic Ice caps increase twice the size of germany in 3 years. Greenland was green less than 400 years ago, and has still not returned to being green. Calmest weather in over a decade, despite claims of increasing wild weather caused by AGW. The "Economist" (your source) just put out a paper about the junk science called Global Warming. Search "The Fiction of Climate Science," where a climatologist talks about the global cooling scare of the 70's (which the current science czar perpetuated in his book about eugenics), the ozone hole of the 80's, and the morphing of "global warming" into "climate change," because the data will not cooperate.

So, it's believe admitted liars and their, "peers," and pay carbon taxes, and participate in a cap and trade scheme where all the money goes to the World Bank and IMF to form a one world fascist dictatorship government, or believe your own lying eyes, and call them criminals! I choose that latter.

Dr Teri O'Brien :

Kim Peart :

04 Dec 2009 6:29:24am

Pumping sulphur into the atmosphere would have a predictable Achilles heel, if a volcano pumps a similar volume into the air, temperatures would then plummet and crops fail. The Royal Society study also suggests the construction of a sunshade in space at La Grange 1. This would be the safest form of geo-engineering to cool the planet and would also be adjustable. A You Tube film can be found on this. A sunshield would also be a good idea for the longer-term with our Sun getting steadily warmer with age, now 25% hotter than at the dawn of life 3.5 billion years ago. Obviously the Earth systems have to continually adjust to a warming Sun and natural history records swings between snowball Earth and a desert planet. We have been in paradise since the end of the last ice age and now our success as a species and civilization are having an impact on the Earth systems that James Lovelock warns, with our slowly warming star, could throw the environmental levers toward a permanently hotter planet.

Unfortunately for humanity, we are confined to a flat Earth, within a tiny layer of atmosphere, but we live in a Solar System that is much larger than our Earthly nest and we will need to use our steadily advancing technology to ensure our survival. Japan is planning to have a solar power station in space by 2030, where the Sun's energy is 5 times stronger than on the Earth's surface, with power beamed to Earth by microwave or laser. This approach could supply all Earth's energy needs indefinitely, allow fossil fuels to remain fossils and avoid the nuclear option, especially with the fuel becoming hard to get. Australia, the lazy space nation, should wake up and invest in this.

It is hardly appreciated that we are now in the midst of a gold rush for the resources of space, including the Moon, asteroids and Mars. India, China, Russia and the United States have all declared their hands and the year all this comes to a head is around 2020. Though the world went into economic meltdown, space investment did not shrink and Russia is doubling its production of spaceships. Securing a permanent and sustainable presence in space will be the key to mastering climate change and ensuring our survival on Earth and in space. In a hotter world we may need to start building on Earth more as if we were living in space.

We need plan A, to reduce greenhouse gases ASAP, but it would be a suicidal gamble to rely on this alone working. We need plan B, to cool the Earth in a controllable way and this would be best secured with a space sunshade. We also need plan C, to ensure our future beyond the Earthly nest, so as to place ourselves in a confident position to fight for a healthier Earthly environment. We need to expand our thinking and planning to the 4 dimensions of space and time, as confining our view to the 2 dimension of the Earth's surface could prove to be the death of us, just like in the documentary drama 'The Age of Stupid.' We can do better

shine :

04 Dec 2009 6:56:07am

oh my god it never seems to amaze me anymore, the lies and manipulation,who gives any one the right to play around with our lives in this way.these hot headed so called educated by the system people have no real idea what there doing nor the long term out come, i mean lets look at the history of science. full of broken promises and narrow testing.almost everything they say they can fix in the end it ends up causing us more problems than before, just look at the way our food is lossing its nutritional values because of incorrect mislead assumptions and cost gutting so the rich can get richer .one day all this hot headed ego money driven people will be gone and it will be our children who are paying and suffering due to the extream stupidness of "Science" HA!i think we all should stop believing in everything those above us are saying and begin to educate yourself, go out of your way to look into things, not just for a few hours take it over a long period, the truth is there in almost everything and the more you read and the more you begin to understand the more power you hold over your own life and your own choicesKnow Your Rights :_)

Kim Peart :

04 Dec 2009 12:22:38pm

Science is only the trail or questions leading to a clearer understanding of Nature. It is what we do with the knowledge as a society, whether commercially or politically, that determines how scientific discoveries are used. Condemning science will not change the need for the trail of questions that leads to a clearer understanding of our Universe. Without science, would we have computers and the Internet to communicate these ideas? We cannot use science and in the same breath condemn it. I see hope for the future, if we will act effectively using science to plan ahead for human survival and prosperity on Earth and across the Solar System. If we remain trapped in flat-Earth thinking, the best we may hope for is Russian roulette with risky geo-engineering ideas.

Eclipse Now :

10 Dec 2009 8:32:36am

Hi Shine,had a nice rant now?

Anything of substance to say?

The thing is, global warming MAY just get so bad that we need to turn to drastic solutions. While I'd prefer they didn't need to because everyone magically agreed on action at Copenhagen, I've become somewhat cynical that all that political hot air will amount to anything.

Plan B may just be necessary, and having a big old rant on an ABC forum doesn't change the science, OK?

Warren Jaenke :

Lester :

11 Dec 2009 3:31:30am

I do believe your right, but as we elimanate the other oxygen breathing species of our great planet there may be enough air but I don't believe mother earth will allow terraforming to suit our needs. That isn't how God built this place.

hmmmm :

Kevin Aldcroft :

04 Dec 2009 12:18:57pm

Global wrarming and climate change is an undoubtable fact. Are Human activities influencing climate change, I believe so. The question is then how much is human activities responsible for the present climate change. The earth has been through several mini ice ages since the end of last great ice age, what caused these events is still unclear, we have a few theories with soil and ice samples but still only theories. Recently an iceberg was seen passing the coast of newzealand this has not occured since I think it was 1910. What happened prior to 1910 to cause the ice to break up in such a large chunk then? During the age of the dinosaures there was no ice at the poles yet the earth cooled sufficiently since then to allow ice at the poles? what I am getting at is the earth appeares to be cycling through hot and cold climate change events. we were not responsible for the the warm climate during the age of dinosaures. We were not responsible for the many climate change events since the the last ice age. Yes we need to cut our CO2 emissions and our reliance on fossilfules. But I think the planet will go through these events regardless of what we do. Some scientist believe that emissions produced today will still be in the atmophere for the next fifty years, having said that even if we were to stop producing co2 right now, then the effects of what we have produced today will still have impacts fifty years from now. What ever happened to all of the work being done using Hydrogen as a fuel. I still wonder if all of the altenative power source inventions have not just simply been bought up to by the big oil companies and still sit in a safe somewhere so the oil companies have a back up plan when oil production is no longer feasable.

Bulldust :

05 Dec 2009 9:02:44am

Kevin:

You summed up everything you said with the words "I believe." What you should do is look up "ClimateGate" on Google and do a bit of research. The messages from the IPCC which so many people dearly wish to "believe" have a nasty stench of fraudulent science attached to them.

With the most important piece of Australian legislation hanging in the balance until next year I charge the ABC (based upon their Charter) to play the role of educator. I think the ABC should hold a series of debates with experts from various fields and explain to Australians:

1) How an ETS would work (or not if Dr Splash of former CSIRO fame can be heard);

2) What the ETS will realistically cost households;

3) What the ETS will cost industry (and hence the likelihood of job losses);

4) Who the stakeholders are in the ETS (i.e. follow the money);

5) I could go on with numerous interesting questions.

Once again, as the single most important piece of legislation facing Australians, why does the ABC ignore its own Charter and fail to educate us on this issue?

Most Australians (check the polls) do not have the foggiest idea what the ETS is all about... time to do something about this appalling situation.

Eclipse Now :

10 Dec 2009 8:34:23am

Bulldust, you're the "true believer" here if you subscribe to climate change being the largest most co-ordinated conspiracy theory ever perpetrated on humanity. So called "Climate-gate" can only be "believed" if you're a teenager looking for a Dan-Brown novel to believe in. Grow up!

Mike :

05 Dec 2009 10:16:24am

politicians will never be able to make the decisions required to alleviate CO2 pollution until the Co2 level is past the tipping point.I suggest the scientists who work in the area of Geoengineering keep developing their ideas, because it will be necessary.

Bulldust :

Tipping point? Exactly what is meant by that? A point at which the earth turns into a Venusian landscape?

Tipping points, while intuitively appealing, point to lazy thought processes and poor science.

Ask any geologist what past temperatures and CO2 concentraions have been. To speak of a CO2 tipping point is laughable when CO2 concentrations have been orders of magnitude higher in geological history... and somehow the earth survived. Funny that...

N.B :

10 Dec 2009 8:27:21am

A number of intelectually bankrupt statements bulldust, Tipping points are "the levels at which the momentum for change becomes unstoppable. A well understood term to describe a common phenomena. In this instance the tipping point is the point at which the amount of carbon we have emitted into the atmosphere is at a level where irreversable damage will be done to the environment regardless of any action taken from then on. Some would suggest this has already happened.

If you look at any time in the past when CO2 concentrations were anywhere near the levels they are currently you will find that "The last time carbon dioxide levels were apparently as high as they are today - and were sustained at those levels - global temperatures were 5 to 10 degrees Fahrenheit higher than they are today, the sea level was approximately 75 to 120 feet higher than today, there was no permanent sea ice cap in the Arctic and very little ice on Antarctica and Greenland,"

Bulldust :

12 Dec 2009 8:52:01pm

Common phenomena eh? But somehow how the earth never became a Venusian landscape or a ball of ice. Care to explain that?

CO2 concentrations have been orders of magnitude higher in the atmosphere previously, as you appear to know already, but somehow today... this point in time in Earth's 4 billion year history we are about to destroy the planet with substantially lower levels of CO2 and other trace GHGs?

You seem to grasp the basics of geological climate change, but somehow in these relatively temperate times we are all going to hell in a handcart...

It makes not a jot off sense. Your own statements are contradictory.

PS> There were ice ages in the geological past with higher CO2 concentrations than today... but I suspect you knew this already.

Stuart Dunk :

05 Dec 2009 10:32:55am

A scientific frenzy has grown around 'climategate'. Professor Jones has been forced to step down over leaked emails indicating he has no raw data to back up his 'proof' that temperatures have increased by 0.74 degrees. The raw data was discarded in the 1980's, and he has been using "normalised and value added" data i.e. it is now contaminated data. So do we need to worry about using sulphur or any geoengineering at all? Because the 'proof' of temperatures rising no longer exists. Climate change may be occurring and only good science can define the problem to be addressed, not false statistics based on contaminated data that leads good scientists to try and solve the wrong problem.

Bulldust :

07 Dec 2009 12:06:46pm

With the "hide the decline" you have to be very careful where you point the finger. The thermometer data was used instead of tree-ring temperature proxies beyond the 1960s to hide the divergence (cooling) indicated by the tree-ring data. This is summarised brilliantly here:

The IPCC would have us believe there was no medival warm period... not sure why Greenland is called thusly, or what the people were smoking when they claimed grapes were being grown in northern England...

Trees are very poor thermometers... therefore all the tree-ring proxies that were used to derive the IPCC "Hockey Stick" graphs are bunk. They artificially grafted thermometer readings to the end of the tree-ring data to hide the indicated decline in tree-ring proxy temperatures.

There is also the issue of the fudge factor in the programming... but one issue at a time.

Eclipse Now :

10 Dec 2009 8:58:14am

Ahhh, the usual top 26 myths pushed by Denialists are being recycled here. Good to see you've been reading your Plimer or "What's up with that" and whatever other non-rational anti-science junk you read Bulldust.

But seriously, ALL of these myths were covered years ago by New Scientist.http://www.newscientist.com/article/dn11462-climate-change-a-guide-for-the-perplexed.html

Alan. :

07 Dec 2009 9:06:19am

If warming is the problem, maybe.

It's not.

What we have compromising our weather, is an unrelenting massive cloud of man-made pollution hanging over equatorial Indian Ocean. Its concentration is so dense the sun's rays cannot penetrate to the water below for the necessary creation of evaporation.

Ergo, the moisture factory of the world is out of balance.

It can be corrected but not by restricting the gas CO2, instead reducing the emissions of solids [particulate matter] is the answer to the world's weather woes - and a decades old technology can do the job at a fraction of the cost of the present futile CO2 chase.

Bulldust :

07 Dec 2009 12:08:33pm

Agreed in principal (I am not sure of the case you point out in detail). David Bellamy said as much on ACA a week or so ago. There are REAL environmental problems that could use some money thrown at them (like exceptionally poor land use practices) rather than the "poppycock" (as Dr Bellamy called it) of man made global warming.

MJ :

07 Dec 2009 10:47:07pm

Climate Change was simply a propaganda operation designed to empower the UN with the authority to levy a Global Tax. Since those who tax us, Govern us..we have been led straight into a trap are no being asked to support the creation of the infamous One World Government that everyone thought could never happen.

Eclipse Now :

10 Dec 2009 9:00:13am

MJ, can you please justify this outrageous opinion of yours with a little data? Who is perpetrating this hoax? How have all the world's scientific bodies of any repute come to independently, rigorously, scientifically come to the same conclusions? No, nothing to see here but more paranoid ranting. Move along, move along...

Bulldust :

You are the moderator now? The keeper of the magic tome of truth? Beavis and Butthead are your defence?

I don't think I am the one that needs to group up mate.

What MJ says has been said more eloquently by many others before... he is just a little more to the point and brusque about it.

BTW there is no need for conspiracy... science goes where the money is mate. Governments and companies have poured billions into climate science and so scientists tend to find what they are expected to find. Don't find the right (policy) science and you have a hard time getting more funding. Not a conspiracy... just incentives and consequences. Notice how the Aussie Government even gags CSIRO scientists from speaking out, regardless of their views. Tell me how that is good for science...

David :

Same conclusions huh... Perhaps the reason it seems so consistent for you is that the body of scientific evidence you are referring to is simply your own opinion on what the science says.

I would, as a start, have a look at the University of Alabama in Huntsville's satellite data, draw your own conclusions.

Investigate what is called 'climate sensitivity' studies, the most significant aspect of the entire debate, in which the IPCC is baseless.

Perhaps do some basic research relating to the climate system and the earth's history rather than appealing to a 'consensus' of science which is one, not there and two, scientists who take the position you are implying are implicated with the greatest scientific scandal of our time.

I prefer to look for myself than to be fed second or third hand information, I suggest you do the same.

Mack :

26 Dec 2009 11:09:28pm

@ Eclipse.I happened on this conversation by chance and it seems to me that you are the uber-fanatic in these parts and that the understanding of data might be beyond you at this time? For the benefit of other readers of these comments may I ask that they follow the links posted here by MJ and Bulldust.Seasons Greetings from Ireland.Mack

There are a lot of people putting in hard yards for no pay to keep the data honest on that site, but it is an uphill battle when many climate scientists do not want people looking at the data (hello to the CRU crew).

Some of the discussions will go over most readers heads... but the gist should be pretty clear in both cases.

Russ66 :

31 Dec 2009 12:41:03pm

Although I have spent the last 18 months investigating this issue,and the so-called "science",I will put it quite simply. I grew up in the '70's, and the weather is no different now than it was then. The weather is lovely, the tomatoes are going great guns, and children have full tummies. Cannot ask for more.And Bulldust, i'd love to catch up for a beer - low carb of course!

Oldie2 :

18 Jan 2010 8:23:37am

Russ, I agree. It must be that so many AGW believers are 40s or less & have no awareness of the cycles of climate. I'll join you and Bulldust for that beer.If the earth gets less CO2 plants will starve and so will we!